JPH01146005A - Paved surface for athletic ground or playground - Google Patents

Abstract

PURPOSE: To improve the durability to treading and the water permeability by coating the pavement surface for athletic field and playground with a mixture prepared by distributing and mixing the flexible fiber into bark material small pieces. CONSTITUTION: The pavement surface of a soccer field and the like is coated with a mixture prepared by distributing and mixing the flexible fiber having a length more than an average maximum size of the bark material and having the decay resistance the same as or more than that of the bark material, into the bark material small pieces, whereby the deterioration with age can be inhibited without using the additive material, and the durability to treading and the water permeability can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a paving surface for playing fields or recreational use having a coating comprising flaky bark material.

The term “covering” to “bark covering” is used herein to mean a surface layer consisting of normal deposits of a playground or recreational pavement, according to DIN 18035 (19
73) “Compressed Pavement Surface (Tennenf 1Mch
It is used in a similar sense to the term "compression coating" in "e)".

In European Patent No. 0 096 908 the Applicant discloses a paving surface for playing fields having a coating consisting at least in part of flaky bark material, which paving surface is particularly suitable for football pitches and similar playing fields. High tread resistance is achieved by a construction that combines multiple layers.

Furthermore, for tracks and playgrounds where special trampling resistance is not required, it is known to use bark materials simply in stacks or layers. Known playground surfaces are usually made of bark material (natural or light brown in color) that is undecayed or at most only slightly decayed.

Surprisingly, even with relatively decayed bark material,
Furthermore, it is anticipated by those skilled in the art that particularly when using such bark materials, advantageous coatings will be obtained if the rotting materials are used in conjunction with relatively small amounts of fibers that are themselves relatively resistant to rotting. It turned out to be contrary.

The novel playground or recreational paved surface according to the present invention is
A preferred embodiment of the paved surface of the present invention having the features set forth in claim 1 has the features set forth in claims 2 to 8.

The paved surface of the present invention is preferably used for soccer fields, for example.

The present invention also relates to a new method of manufacturing a playing field or play surface having a coating comprising flaky bark material. The method according to the invention has the features set out in claim 9.

Bark, although of various origins, can be used to decompose either naturally (i.e., unhindered by artificial means) or by manipulating the temperature so that it is optimal for accelerating the decomposition mechanism (e.g., by microorganisms). ) a state is reached under accelerated conditions in which the changes in physicochemical properties conditioned by decay are found to be almost complete before the typical structure of the piece disappears under normal ambient conditions. did.

The use of materials such as those described above to cover playground or recreational pavement surfaces is considered desirable for two particular reasons.

First of all, coatings using the above-mentioned materials do not require the use of additives to inhibit decay, which not only saves costs, but also reduces the risk of additives being introduced into groundwater. is excluded.

-Secondly, coatings made from materials such as those mentioned above actually have their ultimate strength immediately after their manufacture, i.e. coatings made from bark that is not decayed or has not decayed very much; There is less change over time than in

Moreover, it is also unexpected that coatings consisting of decaying bark material usually exhibit useful water permeability only if they contain large amounts of fine decayed bark particles, i.e. more than 50% by weight of particles of <2 mm, for example. It was confirmed that In addition, even if the coating consists of decayed bark material, the water permeability may be reduced, especially if the coating is made from sieved decayed bark material, ensuring that the bark material passes through a sieve with a mesh size of 2 u. It was also confirmed that it is determined by the substructure rather than the covering.

The addition of fibers according to the invention makes it possible to improve the trampling strength of the covering of pavement surfaces for playing fields or playgrounds according to the invention, even when the fiber content is as low as 0.01 to 0.1% by weight with respect to the dry weight of the bark material. The properties with respect to hardness and homogeneity can be very good, with the coating being 10111
For example, it is formed to have a thickness of 30 to 150 zz. Although it is possible to form a thicker coating,
In that case, there is usually no benefit that compensates for the increased cost. For many purposes the preferred fiber content is 0.
．． It is 1 to 5% by weight. Amounts in excess of 10 weights usually do not provide an advantage commensurate with the required cost (the proportions always relate to the dry weight of the bark in the mixture).

In this document III, the term ``textile structure'' is used in a general sense, and this term can be understood in the sense that flexible moldings with arbitrary cross-sections may be in question; It has a longitudinal dimension that is significantly larger than its largest cross-sectional dimension, for example at least 50 times. The fibers are preferably relatively decay-resistant, i.e., do not show any significant change for at least 12 months under normal weather and humidity conditions in a mixture with decaying bark pieces, optionally with additives. .

Suitable fibers for use in the present invention are generally natural or synthetic inorganic or organic fibers, including fibers obtained by cutting plant fibers and/or synthetic fibers, or fibers obtained from fiber ribbons. Specific examples include natural hard fibers such as coconut fibers or timer fibers, synthetic staple fibers consisting of polyalkylenes such as polyethylene or polypropylene, saturated polyesters such as phthalates and glycols, and polyamides such as nylon. It will be done.

Other fibers that are not soluble in water and preferably swell only slightly in water can also be used.

In particular, it is also possible to use recycled materials obtainable by various methods, including cutting, pulping and other finishing methods.

Preferred are fibers that are relatively resistant to decay.

IK rot resistance can be tested in a heating cupboard at a temperature of 35° C., accelerated in the presence of moisture and aerobic or anaerobic rot fungi or bacteria. for a given period, e.g. 3
For example, the color and/or
Or if the strength changes significantly, the corrosion resistance of the test material is relatively low. Relative values are usually sufficient, ie the preferred fibers are not more susceptible to decay than pieces of bark material when tested under the same conditions.

The preferred fiber thickness is 0.01-1N, especially 0.01N, II.
05-0.5u, but this also depends on the tensile strength.

111 degrees (in a determinable range) can be from 1 to 1,000 denier. Generally, fibers are preferred that yield a fibrous structure that is still discernible after 12 months or more in a mixture with bark chips that are left exposed to weathering.

For many applications, for example 50-500. It is preferable to use a fixed amount of fibers, ie without a necessary relationship between the thickness of the coating and the amount of fibers.

This is particularly relevant when relatively long fibers are used. The fibers may be used in whole or in part as bundles or twisted yarns if cost-effective. In other cases, single strands of fibers, yarns or filaments are preferred; if cost permits, structured fibers are suitable.

In order to impart the desired strength to the coating, in particular trample strength, at least the majority of the fibers (i.e. more than 50% of the total amount) must have a length that is greater than the average maximum dimension of the pieces of bark material. . In fact, the number of lines on a small piece of bark is, for example, 0 to
40 mm, 0 to 50 iv or lO to 8 (hx), the fiber length can be determined correspondingly, i.e. an average fiber length of, for example, more than 40 zz, 5011 or 80 zz, generally 50 to 150 zz or more. can be selected accordingly.

For most applications, a large proportion of the coating of the playground or playground pavement surface according to the invention, i.e. more than 50% by weight of the dry component of the coating, in principle from 75 to 100%, consists of bark material. Composed of a mixture with fibers.

As the bark material, it is possible to use decayed material obtained at a temperature of 50 to 80 DEG C. and a decay period of several weeks to several months, left to decay or subjected to some manipulation. On the other hand, it is also possible to use bark materials that have been allowed to decay naturally in the atmosphere under normal ambient conditions, or it is also possible to use mixtures of bark materials with different degrees of decay. The old material obtained in the process can also be used with or without the addition of new material.

The degree of decay of bark material can also be approximately determined by measuring its color. Bark materials that are more or less stabilized by decay are preferred for many applications. Such stabilization is believed to occur when the cellulose component of the bark is sufficiently removed by microbial degradation and the remainder consists mostly of lignin. The normally measurable C:N value of the bark material itself, ie without additives, is preferably at least about 80±10.

Obtaining the decayed bark material from a particular tree species is relatively unimportant, which is also an advantage of the present invention.

Pinus bark is a preferred example, and the -m mixture contains, for example, about 70% by weight of Pinus bark and about 30% by weight of German spruce bark.

Usually, the DIN color card (DI86164) for decaying bark
), practically independent of the origin of the bark, is at least D3, preferably D4 to D6, on the lightness scale.
It is. In contrast, undecayed or only slightly decayed bark material usually has a D value of 1 to 2, with values such as 3 being exceptional.

Distributing the fibers into the preferably decayed bark material or mixing with the material can be carried out by the turning method or in a mixer or shredder. It is possible to use drum mixers or roll mixers or also mixers with rotating distribution elements. A particularly high shearing effect or mixing strength of the dispensing or mixing device is usually not necessary and may be disadvantageous in some cases, for example when using long or "endless" fibers or filaments. Generally, a sufficiently uniform distribution of the fibers in the bark material can be achieved with a mixing time of 10 to 30 minutes. Control points for fiber distribution can be determined by statistically taking samples, weighing the mixture, and washing out the fibers. The average deviation of the 10 samples preferably does not exceed 20% of the average value.

The line numbers shown herein generally refer to the Swiss Industrial Standards (SSV).
Standards) Features 4. :SN 670808 (sieve), SN 6
70810B (sieving test), SN 670812^ (dry sieving) and SN 670814^ (wet sieving)
can be determined according to Screening is carried out and waste is minimized by limiting the running time of the machine (10 minutes).

The CAN ratio is determined as a weight ratio (carbon content:nitrogen content) by elemental analysis of dried bark (nitrogen by the Kjeldahl method; carbon by quantitative determination from CO□) in a conventional manner.

``Dry weight'' refers to the weight of the bark material that can be obtained by drying at 105° C. until the weight remains constant (24 hours).

Mixing can be carried out with the ingredients air-dried, in wet materials, or with the addition of water. The amount of water present or added during mixing usually depends on the distance between the place where the coating is to be formed and the mixer, so that unnecessarily large bulk transports can be avoided.

Since the finished coating usually contains water to near saturation, water is added already during mixing and/or for the first time during coating formation, or alternatively immediately after coating formation. The location and time of addition of the major amount of water can be selected according to economics.

A paved surface for a playing field or playground according to the invention is constructed by applying a filter layer, load layer or compensation layer, optionally with a dynamic layer, as disclosed in European Patent No. 0 096 908, on a conventionally prepared ground or substructure. produced by applying a mixture of bark material and fibers, with or without forming an intermediate layer, optionally using a geotextile as an intermediate layer, and stretching and compacting in a manner customary per se in a deposition process. obtain.

The covering of a pavement surface for a playground or playground according to the present invention comprises:
The material, which avoids the disadvantage of having an poorly mixed appearance, may also contain further components, preferably granular, which, for example, have a particularly sandy sieve size, e.g. It is an inorganic particulate material having a particle size of 2zz or less.

Laboratory tests of the coating according to the invention have shown that not only is there no risk of inconvenience with respect to groundwater, but also that the coating of a playground or playground surface according to the invention can function as a biological filter layer. shows that it can even be applied to purify wastewater in case of emergency.

The visibility required for the fibers used in the present invention and the overall preferable strength are possessed by the organic fibers mentioned above under normal light.
Brittle inorganic fibers may lack these properties. The above properties can usually be easily verified by repeatedly folding the fiber in half and then stretching it again without breaking.

Laboratory tests have made it possible to confirm that the paving surface according to the invention is able to overcome the problems that occur in areas of particularly high mechanical demands when installing known paving surfaces with bark coatings. In these regions, the bark chips can be broken up relatively violently, so that the average chip size in the word region is smaller than in other, less demanding regions.

As a result, the water permeability rate in these areas with high mechanical demands is reduced, and even though the water permeability itself is still sufficient, when it rains relatively heavily, these areas reflect light relatively strongly, thereby making them less suitable for use. This may give rise to the impression that wet areas or even puddles of water may form locally on or in the coating.

Most of them are relatively fine and, for example, most of them have a line number of 0 to 30 (
In a coating made of bark material with a particle size corresponding to II), the use of fibers makes it possible to ensure a sufficient water permeation rate even in the relatively demanding coating areas, practically the same as in the other areas.

Therefore, the fibers in the coating of a playground or playground surface according to the invention should preferably have an average fiber length that is at least approximately equal to the thickness of the coating and that the distribution of the fibers, or the If the mechanical strength of the mass (e.g. a loosely intertwined fiber mat) resembles a model of roots on a pavement surface with a turf cover, it is possible to achieve not only hardening but also uniformity of permeability. Correspondingly, statistically varying fiber positions, including loose entanglements, are preferred for many purposes to a nearly uniform three-dimensional orientation. It is also possible to distribute the fibers in a fixed orientation in the coating, i.e. in the form of, for example, mat- or carpet-like structures, in which the fibers are bonded to each other with varying degrees of strength, in which case the bark material can be distributed, for example by sprinkling. Usually, with respect to paved surfaces for playgrounds, especially soccer fields, the resistance during walking and running due to the coating or the fibers contained in the coating is lower than 5 in the case of paved surfaces for playgrounds with a turf soil coating. It is understood that there is nothing extremely large.

When using natural fibers, the lignin content (measurement method is Il
iigglund, E., “Holzchemie”
,” 2.＾uflage.

5eite 225, or l1alse, 0.
M., “Papier-Journalen,” 1
0/1926/121) is at least 10% by weight
For example, fibers having a content of 10 to 50% by weight or more are preferable.

(Left below) Husband 1 [L] European Patent No. 009 for soccer field pavement
No. 6908, the surface layer was formed from a mixture containing 1.3 kg of coconut fiber per lx l of bark material (piece size O~50zz; dry weight approx. 250 AFI). The mixture was spread in one step to a layer thickness of 10 cz, rolled and saturated with water. The fibers were mixed with the bark material in a drum mixer for continuous operation.

E1 A paved surface of the eel was produced in the same manner as in Example 1, except that the surface layer was formed in two steps. The lower partial layer consisted of bark material mixed with fibers (piece size O~50zz), the thickness of this layer was 8 cx.

Next, a mixture containing no fibers (piece size O~20xz) was spread to a thickness of 2 cm on the lower part without specifically sealing it, and compressed with a roller.

Subsequently, the entire bark coating layer was saturated with water.

In order to carry out tests with the dog JLL, a number of paved surface areas, each approximately 1x'', on a substructure with drainage facilities, were prepared using a mixture of bark material of varying degrees of decay and varying amounts of fibers. It was manufactured by the method shown in 1, and after being saturated with water, its water permeability and trampling strength were examined.

The water permeability test was conducted by pouring approximately 501 water onto the pavement surface to be tested and measuring the time until the light-reflecting water surface located on the coated surface disappeared. When the elapsed time was less than 300 seconds, it was evaluated as "good water permeability", and when it exceeded 500 seconds, it was evaluated as "poor water permeability".

The strength of being stepped on is Satsuka shoes (with drifting spikes)
A load of 401 g was placed on one side of the board, and the degree of sinking was examined and evaluated. When observed from the side, if light could still pass between the tip of the spike and the sole, the covering was evaluated as ``resistant to being stepped on.''

(A> Significantly decayed bark material (piece size 0 to 50
■) and at least 0.5% by weight of coconut fibers (all proportions are based on dry weight), (B)
Bark material that is not very decayed (small piece size O ~ 50zz
) and at least 0.2% by weight of coconut fibers, and (C) a mixture obtained by adding 10% by weight of silica sand to mixture A.

If the fiber content is increased to 2% by weight, the trample strength and water permeability can be significantly improved. At amounts higher than about 2% by weight, no significant improvement is any longer observed.

Claims (10)

[Claims] (1) A paved surface for a playing field or playground having a coating comprising bark material in the form of flakes, at least a majority of which is comprised of a mixture of flexible fibers distributed among the flakes of bark material. A paved surface comprising: at least a majority of the fibers having a length that exceeds the average maximum dimension of the pieces of bark material. (2) The paved surface according to claim 1, wherein the sieve size of the bark material pieces is less than 50 mm, and the length of at least a majority of the fibers is 50 mm or more. (3) A paved surface according to claim 1 or 2, characterized in that the fibers have at least the same decay resistance as the bark material pieces, and at least a portion of the bark material pieces are decayed. (4) 0.0% of the dry weight of the pieces of bark material in which the fibers are in the mixture;
Preferably the coating has a thickness of 30-150 mm and its fiber content is 50-10%.
Claim 1 characterized in that it is 1,000g/m^2
The paved surface according to any one of 3 to 3. (5) The paved surface according to any one of claims 1 to 4, wherein the fibers have a thickness of 0.01 to 1 mm. (6) the pieces of bark material have a C:N of at least about 80±10;
Pavement surface according to any one of claims 1 to 5, characterized in that it has a value. (7) Pavement surface according to any one of claims 1 to 6, characterized in that the pieces of bark material have a degree of decay corresponding to a dark brown humic acid coloration. (8) At least a portion of the fibers are vegetable hard fibers, and/
or an organic synthetic fiber, the paved surface according to any one of claims 1 to 7. (9) A method of manufacturing a paving surface for a playground or playground having a coating comprising pieces of bark material, the coating comprising a mixture of flexible fibers distributed in the pieces of bark material, the A method of manufacturing, characterized in that at least a majority of the pieces of bark material have a length that exceeds the average maximum dimension of the pieces of bark material. (10) The mixture of decayed bark material and fibers is used as a wet coating and/or water is added, preferably to saturation, during or immediately after coating formation. Method.